In addition to the CHEMSEA partners, several other organisations declared their strong interest in the project and their willingness to become Associated Organisations with a clearly defined commitment and an active role in the project. They are also important in terms of granting permits for scientific activities in the respective national waters.

In Poland, the General Inspectorate for Environment (GIOS) will make sure that project guidelines and other results will find application in the realisation of Baltic Sea Strategy. The Maritime Office Gdynia, the authority managing the Polish territorial waters, supports the project and intends to implement CHEMSEA guidelines and other results and tools. The project also has the support of the Marshall Office of Pomorskie Voivodeship and the Department of Security and Crisis Management of Pomeranian Voivodeship will ensure the policy impact on a regional level in Poland. Importantly, the National Sea Fisheries Institute in Gdynia will link project results to the Polish fishery sector.

In Sweden, CHEMSEA is supported by the Swedish Coast Guard, which is the competent authority for response to harmful substances in the sea. They will take an active role in the assessment and characterisation work, providing expertise on CWA-detection methods. The Swedish Geological Survey (SGU) will aid the project by providing geological, environmental and spatial planning information.

In Finland, CHEMSEA has the support of the Ministry of Environment. 

The Nature Research Centre (NRC) at the University of Vilnius, Lithuania will provide their expertise on environmental genotoxicity of CWAs.

CHEMSEA is also supported by the Atlantic Branch of the Shirshov Institute of Oceanology of the Russian Academy of Sciences (AB SIO RAS). AB SIO RAS is the leading source of data on underwater munitions in the Baltic Sea. In cooperation with IO PAS, they will provide their data and expertise on the localisation and other parameters of CWAs.

Additionally, IDUM, the International Dialogue on Underwater Munitions, and SIPRI, the Stockholm International Peace Research Institute, an independent institute dedicated to research and monitoring of munitions related issues, have both declared their willingness to share their experience and networks with the CHEMSEA project.

Last but not least, the HELCOM secretariat is aware of and highly supportive of the CHEMSEA project. Project objectives and activities are well in line with the HELCOM MUNI group, but also HELCOM Response group activities. CHEMSEA is bound to closely cooperate with the  HELCOM MUNI working group in order to create the most synergies and ensure the largest possible impact of the produced results.